With the rapid development of display technologies and the increasingly high requirements of users for display devices such as a smart phone, a tablet computer and a personal computer, it is desired that the display screen should be maximized in a limited space. In order to satisfy the users' requirements, this is now usually achieved by reducing a distance between the display screen and the frame.
FIG. 1 is a schematic section view of the structure of an existing display panel. The section is taken by cross-cutting the display panel by using a plane parallel with any side of the display panel and perpendicular to a display plane of the display panel. Referring to FIG. 1, the display panel comprises a display substrate 1, a first frame 2, an optical substrate 3, a second frame 4, a light guide plate 5 and a back plate 6. The display panel comprises a display region 11 and a black fringe region 12, and the length of the light guide plate 5 is smaller than that of the display region 11. When a backlight source emits light rays, the light rays are reflected to the display region 11 by the light guide plate 5 so as to illuminate the display region 11 such that a user can see contents displayed in the display region 11.
However, the display panel at least has a problem as follows: since the length of the light guide plate 5 is smaller than that of the display region 11, a dark area is formed at a border of the display region 11 close to the black fringe region 12. The light rays reflected by the light guide plate 5 cannot be reflected to the dark area, so the user cannot see contents displayed in the dark area, which results in a poor display effect.